Geometric flow regulator

ABSTRACT

A tubular implant for obstructing blood flow through a blood vessel, ( 110 ) the implant comprising an outer surface having a geometry of a tube, at least a portion of which is adapted for contacting a blood vessel and an inner surface defining a passage through which blood flows, wherein the distance between the inner surface and the outer surface is non-uniform along an axis of said tube.

RELATED APPLICATIONS

This application claims priority from PCT/IL02/00805 filed Oct. 3, 2002,which is a CIP of PCT/IL01/00284 filed Mar. 27, 2001, now U.S. Ser. No.10/239,980 which is a CIP of U.S. Ser. No. 09/534,968, the disclosure ofall of which are incorporated herein by reference.

This application also claims priority from the following applications:Israel Application No. 151162, filed on Aug. 8, 2002, Israel ApplicationNo. 151931, filed on Sep. 25, 2002, U.S. application Ser. No.10/239,980, filed on Sep. 26, 2002, PCT Application No. PCT/IL02/00805,filed on Oct. 3, 2002, Israel Application No. 152366, filed on Oct. 17,2002 and Israel Application No. 153753, filed on Dec. 30, 2002. Thedisclosure of all of which are also incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to devices for partially obstructing bloodflow through a blood vessel.

BACKGROUND OF TH INVENTION

Angiogenesis, is a process by which new arteries are created withintissue to bypass occluded vessels or areas of poor circulation.Angiogenesis does not usually occur to any great degree naturally andvarious procedures have been suggested to encourage it, particularly inthe heart. For example, in coronary tissue, Trans-MyocardialRevascularization (TMR) is a process in which multiple holes are drilledin the heart with the intent of causing new vessels to form.

Constriction of the coronary sinus to reduce the flow of venous bloodthat passes through it to the right atrium has been shown to promoteangiogenesis. (See: “The Surgical Management of Coronary Artery Disease:Background, Rationale, Clinical Experience” by C. S. Beck and B. L.Brofman, American College of Physicians in Annals of Internal Medicine;Vol. 45, No. 6, December 1956.)

Ruiz in U.S. Pat. No. 6,120,534 teaches a stent having a crimped flowpassage for temporary reduction of blood flow in a pulmonary artery of anewborn.

Palmaz in U.S. Pat. No. 5,382,261 teaches a stent having a hollowed,bullet-shaped portion that fully occludes blood flow and promotes clotformation within the hollowed portion.

Mobin-Uddin in U.S. Pat. No. 4,727,873 teaches an embolus trap thatanchors in a blood vessel with wires of uniform thickness.

Carpentier et al. in U.S. Pat. No. 4,106,129, Pavcnik et al. in U.S.Pat. No. 5,397,351 and Bailey et al. in US Patent application2001/0021872 teach wires of uniform thickness that anchor a valve in theheart.

Block et al. in U.S. Pat. No. 5,554,185 teach an inflatable cardiacvalve.

Khosravi, in U.S. Pat. No. 5,925,063 teaches multiple overlapping flapsthat may be configured into a valve, blood filter, blood flow occludingdevice or flow regulator.

Anderson et al. in U.S. Pat. No. 6,168,614 teach a cardiac valve that isexpanded in vivo using a balloon.

The disclosure of all the above-noted prior art is incorporated hereinby reference.

SUMMARY OF THE INVENTION

An aspect of some embodiments of the invention relates to aflow-obstructing implant comprising an outer surface, at least a portionof which is adapted to contact a blood vessel and an inner surfacedefining a flow passage. In an exemplary embodiment, at least a portionof the walls surrounding the flow passage are thickened so as todecrease the mean cross-sectional diameter, providing increased flowobstruction.

In an exemplary embodiment, at least a portion of the implant comprisesmaterials that expand upon absorbing liquid during in vivo implantationso that, for example, the implant expands to a flow-obstructingconfiguration following implantation.

Optionally, the implant comprises a material that compresses underpressure for example when a balloon catheter is inflated against it.Upon inflation of the balloon, the flow passage walls are compressed toincrease the mean cross sectional diameter of the flow passage.

In an exemplary embodiment, at least a portion of the implant comprisesa hollow chamber, for example, adapted to be inflated. Optionally, thehollow chamber is adapted to assume multiple sizes, for example usingvaried inflation pressures, thereby providing different effectivecross-sectional diameters of the flow passage.

In an exemplary embodiment, the axis of the outer surface isnon-parallel to the longitudinal axis of the flow passage so thatoptionally the outer surface configuration conforms to the shape of theblood vessel where the implant is located.

An aspect of some embodiments of the invention relates to aflow-obstructing implant adapted for implantation in a blood vessel,having a wall that defines a flow passage and one or more flapsprojecting from the wall into the flow passage. Optionally, the one ormore flaps may be angularly adjusted with respect to the flow passage,thereby adjusting the flow of blood through the flow passage. In anexemplary embodiment, angular adjustment of the flap position withrespect to the flow passage is made using an inflatable balloon, forexample an inflatable portion of a balloon catheter.

An aspect of some embodiments of the invention relates to aflow-obstructing implant having two or more flow obstructing flapsprojecting therefrom, wherein two or more of the flaps are connected byat least one guide element. In the expanded state, the at least oneguide element is operative to encourage the two or more flaps into aposition in which they partially block the flow passage.

Optionally, the two or more flaps connected to the guide elementcomprise shape memory materials that assume a final stable expandedposition so that the guide elements are no longer necessary for positionencouragement. In an exemplary embodiment, the one or more guideelements may comprise materials that sever, and/or expand, duringadjustment of flap position for example using a balloon catheter.

An aspect of some embodiments of the invention relates to aflow-obstructing implant adapted for implantation in a blood vesselhaving a wall that defines a flow passage and at least one wireprojecting from the wall. In an exemplary embodiment, at least a portionof the at least one wire comprises a width that at least partiallyobstructs blood flow through the passage. Optionally, the at least onewire comprises a hollow tube that, for example, is inflatable.Optionally, the at least one wire comprises a varying effective width.

Optionally, the at least one wire comprises at least two wires, forexample that are interconnected. In an exemplary embodiment, the two ormore wires are connected to a curved junction, for example a plate withcurved edges, for the purpose of reducing turbulence in blood flow.Optionally the two or more wires incorporate a substantially volumetricobject, for example a sphere.

There is thus provided a tubular implant for obstructing blood flowthrough a blood vessel, the implant comprising an outer surface having ageometry of a tube, at least a portion of which is adapted forcontacting a blood vessel and an inner surface defining a passagethrough which blood flows, wherein the distance between the innersurface and the outer surface is non-uniform along an axis of the tube.

In an exemplary embodiment, at least a portion of the inner and outerwalls are continuous. Further, at least one portion of the distance ishollow. Optionally, the at least one hollow portion is adapted to beinflated.

In an exemplary embodiment, at least one of the outer and inner surfacesis parallel to the longitudinal axis of the flow passage. Optionally, atleast one of the outer and inner surfaces is non-parallel to thelongitudinal axis of the flow passage.

There is thus further provided an implant for obstructing blood flow ina blood vessel, the implant comprising a tubular wall defining a flowpassage adapted for encircling a flow of blood through a vessel and oneor more positionally adjustable flaps projecting from the wall into theblood flow. In an exemplary embodiment, the one or more flaps comprisetwo or more flaps.

There is thus further provided an implant for obstructing blood flow ina blood vessel, the implant comprising a tubular wall defining a flowpassage adapted for encircling a flow of blood through a vessel two ormore positionally adjustable flaps each connected at one end to thetubular wall and one or more guide elements connecting the two or moreflaps, operative to maintain the two or more flaps in a position inwhich they partially block the flow passage.

Optionally, the one or more guide elements deform or break underpressure. Alternatively the one or more guide elements comprise two ormore guide elements. Optionally, the two or more guide elements havedifferent pressure thresholds at which they deform or break.

There is thus further provided an implant for obstructing blood flow ina blood vessel, the implant comprising a tubular wall defining a flowpassage adapted for encircling a flow of blood through a vessel and atleast one non-overlapping flap projecting from the wall into the bloodflow.

In an exemplary embodiment, the at least one flap is substantiallyplanar with a surface of the tubular wall. Optionally, the at least oneflap is substantially non-planar with a surface of the tubular wall.Alternatively or additionally the at least one flap is positionallyadjustable.

In an exemplary embodiment, the at least one flap comprises at least twonon-overlapping flaps. Optionally, the implant comprises a kit thatadditionally includes a flap angle adjusting tool, the tool comprising ashaft having one or more wing projections adapted to press against oneor more flow obstructing flaps. Optionally, the one or more wings of thetool are activated in one or both of mechanically and inflatably.

There is thus further provided an implant for obstructing blood flow ina blood vessel, the implant comprising a tubular wall defining a flowpassage adapted for encircling a flow of blood through a vessel andleast one wire of varying effective width adapted to at least partiallyobstruct blood flow.

Optionally, the at least one wire curves in a plane of the width of thewire. Alternatively or additionally, the at least one wire is connectedto an object. Alternatively or additionally, the at least one wirecomprises at least two wires. Optionally, the at least two wires areinterconnected, for example, the interconnection comprises at least onecurved member.

In an exemplary embodiment, at least a portion of the implant is adaptedto change configuration upon absorption of fluid. Alternatively oradditionally, at least a portion of the implant comprises resilientmaterials.

In an exemplary embodiment, at least a portion of the implant comprisesshape memory materials. Alternatively or additionally at least a portionof the implant is adapted to be inflated.

There is thus provided a method of modifying an implant geometry, of atubular implant with at least one intra-luminal flap, comprisingcontacting at least one intra-lumen flap of an implanted vascularimplant with an effector element and bending the flap by applying forcevia the contact. Optionally, contacting comprises pulling the elementtowards the flap. Alternatively or additionally, contacting comprisespushing the element towards the flap.

In an exemplary embodiment, pushing comprises pushing with enough forceto tear an element restraining of the flap. Optionally, the elementcomprises a mechanically expandable element. alternatively oradditionally the element comprises a mechanically expandable element.

There is thus provided an implant comprising a radially expandabletubular sheath and at least one flap welded to the sheath and configuredto at least partially and rigidly obstruct a lumen of the sheath.Optionally, the tubular sheath comprises a wire mesh sheath. In anexemplary embodiment, the implant comprises at least two flaps andcomprising at least one restraining element interconnecting the flapsand limiting their movement relative to each other. Optionally, therestraining element is adapted to be torn by applying force to one ormore flaps, while implanted.

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplary non-limiting embodiments of the invention are described in thefollowing description, read with reference to the figures attachedhereto. In the figures, identical and similar structures, elements orparts thereof that appear in more than one figure are generally labeledwith the same or similar references in the figures in which they appear.Dimensions of components and features shown in the figures are chosenprimarily for convenience and clarity of presentation and are notnecessarily to scale. The attached figures are:

FIG. 1 is a longitudinal cross section of a flow-obstructing implantinstalled in a blood vessel, in accordance with an exemplary embodimentof the invention;

FIGS. 2A and 2B are isometric views of two embodiments offlow-obstructing implants with flaps, in accordance with an exemplaryembodiment of the invention;

FIGS. 3A-3D are various embodiments of flow-obstructing implants havingnarrowed passages, in accordance with an exemplary embodiment of theinvention;

FIG. 4A-4C are various embodiments of flow-obstructing implants havingwires, in accordance with an exemplary embodiment of the invention;

FIGS. 5A and 5B are implants with guide elements spanning the flowobstructing flaps, in accordance with an exemplary embodiment of theinvention;

FIGS. 6A-6D are an embodiment and operation of a tool that adjusts theangle of flow-obstructing flaps, in accordance with an exemplaryembodiment of the invention; and

FIGS. 7A-7C are an alternative embodiment and operation of a tool thatadjusts the angle of flow-obstructing flaps, in accordance with anexemplary embodiment of the invention.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Thick-Walled Implant

FIG. 1 is a longitudinal section of a flow-obstructing implant 100installed in a blood vessel 110, comprising an outer wall 102 and aninner wall 104 and a cylindrical ring 130 comprising solid materialbetween walls 102 and 104. In an exemplary embodiment, inner wall 104defines a lumen 114 that is narrower in diameter than a blood vesselpre-implant diameter 112, thereby reducing blood volume in apost-implant area 118 as blood flows in a direction 116.

In an exemplary embodiment, implant 100 is implanted in a coronary veinand the reduction of blood flow promotes angiogenesis in an area ofcoronary tissue 120. Further details of angiogenesis are provided in“The Surgical Management of Coronary Artery Disease: Background,Rationale, Clinical Experience” by C. S. Beck and B. L. Brofman,American College of Physicians in Annals of Internal Medicine Vol. 45,No. 6, December 1956.

Alternatively or additionally, implant 100 is implanted in othervessels, for example arteries, the coronary sinus, portal vein, hepaticand/or other veins.

In an exemplary embodiment, inner wall 104, chamber ring 130 and/orouter wall 102 comprise shape memory materials that automatically expandwhen released from a compressive force. Implant 100, for example, isdelivered to the deployment site in blood vessel 110 in a compressedsize inside a delivery catheter 122. Upon reaching the in situ area,implant 100 is freed of delivery catheter 122 and expands automatically.

Alternatively or additionally, inner wall 104, ring 130 and/or outerwall 102 comprise materials that absorb liquid, for example, from theblood flowing through blood vessel 110 and change size and/orconfiguration as a result of the absorption. In an exemplary embodiment,implant 100 is delivered in a compressed state to the delivery site,freed of catheter 122 and absorbs liquid to expand into its finalconfiguration.

Optionally, at least a portion of wall 104 comprises a material that canbe compressed and/or deformed under pressure. A balloon catheter, forexample, is expanded in lumen 114, thereby increasing the flow passage.

In an exemplary embodiment, walls 102 and 104 comprise a flexiblematerial and ring 130 comprises an inflatable area (e.g. a hollowchamber). To inflate ring 130, fluid is pumped into ring 130 usinginflator hose 126. Upon completion of inflation, inflator hose 126 ispulled free of implant 100 and an inflator seal 128 automatically sealsimplant 100. Optionally, chamber 126 can be inflated to two or moresizes, thereby providing variably obstruction to blood flow.

In an exemplary embodiment, inflator hose 126 is left in place for aperiod of time, for example 24 hours, during which the changes in bloodflow volume, pressure and/or other factors are measured. Consideringthese measurements, implant 100 is inflated and/or deflated to provideto achieve a desired obstruction.

Implant Having Flaps

FIGS. 2A and 2B are isometric views of obstructing implants 230 and 240comprising three non-overlapping flaps 232, 234 and 236 that allow bloodflow, for example, between their adjacent borders. Optionally, flaps232, 234 and 236 are configured without sharp edges along their bordersprojecting into the blood flow so that turbulence in blood flow isminimized.

Implant 240 comprises flaps that are skewed in relation to outer wall102. The skewed relationship of implant 240 allows the extents of flaps232, 234 and 236 around an axis running through lumen 114 to be enlargedto a maximal extent without overlap between the flaps. Implant 230comprises flaps 232, 234 and 236 that are not skewed in relation toouter wall 102 but the angle governing their projection into lumen 114may be adjusted.

In an exemplary embodiment, at least one flap 232 is adjustable in anangle 270 with respect to implant 230 or 240. For example, followingimplantation of implant 230 or 240, a balloon catheter is placed inlumen 114 and inflated so that it presses against flap 232. As theballoon is inflated, angle 270 decreases and flap 232 provides lessobstruction to blood flowing through lumen 114. Alternatively oradditionally, changing the angle of flap 232 encourages the walls of thesurrounding vessel 110 (FIG. 1) to collapse around the flaps, providingbetter anchoring of implant 230.

In an exemplary embodiment, by inflating a balloon catheter adjacentflap 232, the skew angle of flap 232 in implant 240 is adjusted, forexample encouraging anchoring in vessel 110.

Optionally, changes in the flow of blood during adjustment of theposition of flap 232 are measured, for example using an angiogram, andpositional adjustment of flap 232 is made until an appropriate bloodflow is achieved. For further details on achieving proper blood flowobstruction, see “Implant Installation Technique”, below.

Alternatively or additionally, a balloon catheter is moved in direction116 (FIG. 1) until it presses against the front of flap 232. As theballoon is inflated, flap 232 is pushed into lumen 114. As angle 270increases, the flow of blood through lumen 114 is reduced. Optionally,flaps 232, 234 and 236 are interconnected with a flexible membrane thatincreases the obstruction area of the flaps. As flaps 232, 234 and 236move, the membrane expands or contracts.

Flaps with Restraints

FIG. 5A is an embodiment of a flow-obstructing implant 500 having:

-   -   flaps 232, 234 connected by a guide element 562;    -   flaps 234, 236 connected by a guide element 564; and    -   flaps 236, 232 connected by a guide element 560.

In an exemplary embodiment, guide elements 560, 562 and 564 arepositioned substantially close to the edges of flaps 232, 234 and 236that are closest to the center of lumen 114.

Guide element 562, for example, cause flaps 232 and 234 to offset fromwall 104, and project into lumen 114 when implant 500 is expanded insitu. Alternatively or additionally when flaps 232 and 234 extend beyondfront edge 106 then when implant 500 is expanded, guide element 562cause flaps 232 and 234 to be at an angle to the radial axis of implant500.

Optionally, flaps 232 and 234 are configured from a shape memorymaterial so that following expansion of implant 500, attachment to guideelement 562 becomes unnecessary.

Optionally, the angle of 232 and 234 may be adjusted using an adjustingtool 600 or 700, as described below and guide element 562 comprises amaterial that severs and/or expands under pressure. In such embodiments,during adjustment of the angle of flaps 232 and 234, guide element 562is severed or stretched. Alternatively or additionally guide element 562may comprise a biologically dissolvable material that dissolves in vivoover a period of time.

FIG. 5B is an embodiment of a flow-obstructing implant 500 having:

-   -   flaps 232, 234 connected by a guide element 552;    -   flaps 234, 236 connected by a guide element 554; and    -   flaps 236, 232 connected by a guide element 550.

In an exemplary embodiment, guide element 550 is positioned relativelyclose to front end 106, reducing its size over guide element 560. Byreducing the size of element 550, blood turbulence may be reduced.

Optionally, flaps 232 and 234 may be connected by two guide elements,552 and 558. Elements 552 and 558 optionally sever and/or expand atdifferent pressures during adjustment of flap angle. Alternatively oradditionally, elements 552 and 558 are of different lengths. In anexemplary embodiment, when a balloon catheter is inflated to a firstcircumference, flaps 232 and 234 move outward and guide element 558expands and/or severs so that flaps 232 and 234 maintain a firstexpanded circumference with respect to wall 102.

In an exemplary embodiment, a balloon catheter is inflated to a secondcircumference, flaps 232 and 234 move outward to a second expandedposition and guide element 552 expands and/or severs. With both guideelements 552 and 558 expanded and/or severed, flaps 232 and 234 assume asecond expanded circumference with respect to wall 102.

Angle Adjusting Tool

FIGS. 6A-6D show use of flap angle adjusting tool 600, for exampleincluded in a kit together with implant 500. Adjusting tool 600comprises a hollow tubular shaft 602 connected to inflatable wings 610and 620. In an exemplary embodiment, adjusting tool 600 is transportedin delivery catheter 122 with wings 610 and 620 retracted, as seen inFIG. 6A. Upon reaching implant 500, adjusting tool 600 is pushed forwardin a direction 630 until wings 610 and 620 are beyond catheter 122.

In FIG. 6B, a fluid passes through tubular shaft 602 and causes wings610 and 620 to open (moving in a direction 632) so they project radialoutward of the axis of shaft 602. As seen in FIG. 6C, adjusting tool 600is pulled in a direction 634 so that wings 610 and 620 press againstflaps 232 and 234 causing angle 270 to increase, thereby increasingobstruction of blood flow.

Alternatively or additionally, wings 610 and 620 may be positioned inlumen 114 and pressed in a direction 630 against flaps 232 and 234,causing angle 270 to decrease, thereby reducing blood flow obstruction.

In FIG. 6D, collapse of tool 600 is shown. Wings 610 and 620 have beenmade non-rigid, for example by removing fluid from wings 610 and 620 viatube 602. Adjusting tool 600 is then pulled in a direction 634, causingwings 610 and 620 to extend beyond shaft 602 as tool 600 is pulled intodelivery catheter 122.

FIGS. 7A-7C show use of an alternative embodiment of an adjusting tool700 that is activated mechanically. In an exemplary embodiment, wings610 and 620 are rotatably attached to a shaft 702, for example withspring hinges 740 and 750. Adjusting tool 700 is transported in catheter122 and moved in direction 630 so that it is beyond catheter 122allowing spring hinges 740 and 750 to cause wings 610 and 620 to expandradially outward in direction 632 (FIG. 7B).

With wings 610 and 620 in the expanded position, adjusting tool 700 isused to modify the position of flaps 232 and 234. Optionally, this canbe accomplished either by pulling tool 700 in direction 634 against theforward aspect of flaps 232 and 234. Alternatively tool 700 may bepushed in direction 630 against the lumen-facing surfaces of flaps 232and 234.

Optionally, removal of tool 700 is accomplished by pulling tool 700 indirection 634 into catheter 122, causing wings 610 and 620 to extendbeyond shaft 702 (similar to the position of adjusting tool 600 in FIG.6D). In an exemplary embodiment, the pressure required to cause thecollapse of wings 610 and 620 is greater than the pressure exertedduring adjustment of the angle of flap 232 so that wings 610 and 620 donot inadvertently collapse during the adjustment.

In an alternative exemplary embodiment, wings 610 and 620 are connectedto a collar 632 by struts 642 and 652 and collar 632 is connected to auser-operated wire 760. By pulling wire 760 in direction 634 withrespect to shaft 702, collar 632 moves in direction 634, so that wings610 and 620 collapse in a direction 732 against shaft 702.

Adjusting tool 700 with collapsed wings 610 and 620 is pulled intocatheter 122 and removed from the vicinity of implant 500 (FIG. 6C) andout of the patient.

Narrow Passage Implant

FIGS. 3A-3D show various embodiments of implants 330, 350, 360 and 370,having a narrow opening 364 that obstructs blood flow rather than, forexample, individual flaps 232 of implant 230. In an exemplaryembodiment, the material surrounding passage 364 is flexible so thatpassage 364 can expand under pressure. In an exemplary adjustmentprocedure, a balloon is inflated in passage 364, thereby causingexpansion of the flexible material so that passage 364 increases indiameter.

The various embodiments of implants 330 may have specific designs foruse in a specific blood vessel environment For example implant 370 (FIG.3D) that has a tapered section 376 may be suitable for use in a taperedblood vessel.

Implant 330, 340, 350 and 360 have front walls 106 that curve towardopening 364 into lumen 114, for example encouraging the blood vessel tocollapse around the implant so that it doesn't shift followingimplantation.

Implant 360 demonstrates a tapered section 366 that reduces the internalvolume of passage 114 along flow path 116 possibly enhancing theangiogenic affect by causing pooling of blood after it passes throughopening 364.

In some cases, pooling of blood inside lumen 114 is desired to enhanceangiogenesis. To this end, implant 360 may be reversed in itsimplantation in a blood vessel so that blood in lumen 114 causesincreased backflow pressure as the blood flow is obstructed from passingthrough (exit) opening 364.

Implant 370 demonstrates tapered section 376 and has its opening 264 atend 108 with respect to blood flow 116 that similarly increase poolingof blood in lumen 114. Angiogenesis may be increased by any combinationof increased pressure, pooling and backflow of blood.

Implant 330 shows a front wall 332 having a difference thickness and/orcomprising a different material than wall 102 and/or ring 130. In anexemplary embodiment, front wall 332 comprises a machined surface thatencourages tissue ingrowth, thereby promoting implant 330 to anchor inthe blood vessel.

Optionally, front wall 332 comprises a shape memory material that foldsor compresses to fit inside catheter 122 (FIG. 1). Walls 102 and 104optionally comprise a material with resilient properties. Upon releasefrom catheter 122, wall 332 unfolds and assumes its implanted shape,encouraging resilient walls 102 and/or 104 to assume their implantedconfiguration.

Shape memory materials may include, stainless steel mesh, surgical gradetitanium and/or other metals. Alternatively or additionally, implant330, including walls 102 and 104, may comprise a resilient materialhaving a jacket of steel mesh surrounding outer wall 102. In anexemplary embodiment, the mesh jacket provides a surface that enhanceanchorage into blood vessel 110 (FIG. 1).

Implant Having Wires

FIGS. 4A-4C are isometric views of implants 630, 640 and 650, comprisingat least one flow obstructing wire 232 that curves in the plane of thewidth of wire 632.

In exemplary embodiments, as shown in implants 630 and 640, at least onewire 632 is connected to a plate 642. Optionally, flow obstructing wire232 comprises four wires, 632, 634, 636 and/or 638 that are connected toplate 642. In an exemplary embodiment, plate 642 provides obstruction ofblood flow. Alternatively or additionally plate 642 may comprise an openring that serves as a junction of wires 632, 634, 636 and/or 638 tominimize turbulence of blood flow that may occur when the wires arejoined without a ring to which they are connected.

Alternatively or additionally, wires 632, 634, 636 and/or 638 comprisesflat ribbon-like elements, for example, that have varying effectivewidth when laid out in a flat plane.

In implant 650, at least one wire 632 is connected to a volumetricobject, for example a sphere 674.

In an exemplary embodiment, the cross-sectional shape of sphere 674and/or plate 642 may comprise any one of a variety of sizes and/orshapes for example flat spheroid, triangular or square. These and othershapes of sphere 674 and/or plate 642 may be chosen, based upon theamount of flow obstruction required and/or turbulence (or lack ofturbulence) desired.

Optionally, plate 642, sphere 674 and/or wire 632 comprise a materialthat expands upon absorbing a liquid. Alternatively or additionally,sphere 674, wire 632 and/or wall 102 are inflatable and implant 650 isinflated, for example, using inflator hose 126 (FIG. 1).

Implant 640 shows details of plate 642 that comprises curvatures 652,654, 656 and 658 that smooth the interconnection between the wires andplate 642, thereby reducing blood turbulence. Alternatively oradditionally plate 642 and/or sphere 674 may not be centered withrespect to lumen 114 and/or may comprise more than one plate 642 and/orsphere 674.

Implant 630 is shown with a front end 106 being thickened with respectto a rear end 108 of implant 640, thereby adding to the obstruction ofblood flow. Front wall 106 is shown as being planar and perpendicular towall 102. In an alternative embodiment, wall 106 is sloped into lumen114 or may have a curved surface. The thickness and/or configuration ofwall 106, may be influenced by a variety of factors including the bloodpressure and/or the thickness of the blood vessel walls.

Wire Construction

For simplicity, reference will be made to construction of single wire632, though such references could apply to wires 634, 636 and/or 638 aswell. In an exemplary embodiment, wire 632 is resilient so that it foldsinto a compressed state while implant 630 is compressed within deliverycatheter 122. Optionally, resilient wire 632 automatically forms into apre-determined configuration shape upon exiting catheter 122 (FIG. 1),for example independent of the expansion of wall 102.

In an exemplary embodiment, wire 632 comprises flexible material whoseshape, for example, is determined by the amount of drag in the bloodflowing around it. In an exemplary embodiment, wire 632 moves accordingto changes in blood flow and/or blood pressure during the cardiac cycle.

Wire 632 is shown at front end 106 though it could be located anywherealong lumen 114, including rear end 108. Wire 632 is shown projectingforward of front end 106, though it could be perpendicular to outer wall102 or even project into lumen 114, for example as a result of bloodflowing into lumen 114.

Optionally, wire 232 comprises a tube that has a varying effective widthand may, for example, be altered by inflation or deflation. In anexemplary embodiment, for example wire tube 232 has a fixed narrowattachment to plate 634 while the remainder of wire tube 232 has aneffective diameter that increases in response to inflation. Inflation ofwire tube 232 initially may result in a tube that of uniform effectivediameter while increased inflation may cause an increase in effectivewidth of at least a portion of wire tube 232 beyond the area of itsattachment to plate 634.

In an exemplary embodiment, wire 632 tube inflates to and/or comprises awidth of between 0.1-1 millimeters (optionally less than 0.1 millimetersor more than 1 millimeter) to provide obstruction of blood flow.

In an exemplary embodiment, plate 642 has an area of between 0.5 and 1.0square millimeters (optionally less than 0.5 square millimeters or morethan 1 square millimeter) to provide obstruction of blood flow. In anexemplary embodiment, sphere 674 comprises a volume of between 0.1-1cubic millimeters (optionally less than 0.1 cubic millimeters or morethan 1 cubic millimeter) to provide obstruction of blood flow.

Further changes in effective area of wire 632, sphere 674 and/or plate642 are contemplated for the purpose of modifying the blood flowobstruction.

Implant Materials

In an exemplary embodiment of the invention, implant 100 is cut out of asheet of metal or a tube, for example, using laser, water cutting,chemical erosion or metal stamping (e.g., with the result being weldedto form a tube). Alternatively or additionally one or more of flaps 232are welded to surface 104 or edge 108 or 106 of implant 100. In anexemplary embodiment, as implant 100 expands, for example duringimplantation, the distance between flaps 232, 234 and 236 increases ordecreases based upon the amount of expansion of implant 100.

Alternatively or additionally, implant 100 is woven (e.g., of metal orplastic fiber), for example, using methods well known in the art.

In an exemplary embodiment of the invention, implant 100 is formed ofmetal, for example, a NiTi alloy (e.g., Nitinol) or stainless steel(e.g., 316L and 316LS). Alternatively, implant 100 is formed of, orcoated with, other biocompatible materials, such as nylon and/or otherplastics. Optionally, implant 100 is formed of two or more materials,for example, inner wall 104 being formed of plastic and outer wall 102being formed of metal.

Optionally, an outer surface 124 (FIG. 1) is manufactured with amachining process and, for example, etched in a pattern on at least aportion of an outer surface 124, so that it anchors against blood vessel110. Alternatively or additionally, outer surface 124 is fashioned withknobs and/or indentations that promote ingrowth of tissue 120 that aidin anchoring implant 100. Alternatively or additionally, the diameter ofouter wall 102 may be varied along its length to conform to contact aportion of blood vessel 110 when blood vessel 110 has, for example, avariable configuration and/or diameter along its length.

In embodiments including inflatable ring 130, implant 100 may comprisesflexible materials, for example silicone. Alternatively or additionally,implant 100 may comprise embodiments that enhance anchoring in vessel110 (FIG. 1). For example, along opening 108 and/or 104, serrations maybe provided that enhance anchoring into vessel 110. Alternatively oradditionally, wall 102 may be roughened to enhance anchoring. Providingserration and/or roughening to implant outer wall 102, for example, maybe accomplished by any one of a variety of methods known in the art,some of which are detailed below.

In an exemplary embodiment, implant 100 comprises materials that preventcoagulation, embolism formation and/or bacterial colonization and, arereleased over a period of time. The time release of the materials may beset in advance so that release occurs over a period of one month or moreor two weeks or less, depending, for example on the patient state ofhealth.

Determining Implant Size

In an exemplary procedure used in an embodiment of the presentinvention, an angiogram is made that includes the flow through bloodvessel 110. The shape and/or cross sectional diameters of blood vessel110 are determined from the angiogram and an implant 100 having anappropriate size, shape and/or configuration is chosen to be implanted.

For example, the outside diameter and configuration of implant 100 arematched to the inside diameter and configuration of blood vessel 110 toprovide an optimal fit with blood vessel 110. Further, the crosssectional configuration of lumen 114, for example, is matched to theprofile of obstruction determined to provide the best results.

Alternatively or additionally, once implant 100 is in place, anangiogram of blood vessel 110 is made and one or more changes are madeto change blood flow through passage 114, for example, using a ballooncatheter. Changes in implant 100 may be accomplished, for example byinflating a balloon in lumen 114 and/or in proximity to front end 106 asnoted above. Adjustment of implant 100 may affect one or more of:

-   -   walls 102 and 104;    -   flaps 232, 234 and 236;    -   wires 632, 634, 636 and/or 638;    -   ring 130; and    -   lumen 114.

In an exemplary embodiment, a desired change in the blood volume isaccomplished by volumetric measurements. For example, to achieve a 50%reduction in blood flow, the cross sectional diameter of blood vessel110 is determined from the angiogram. In an exemplary embodiment,implant 100 is manufactured with different diameters of lumen 114 and animplant 100 with an appropriate diameter of narrow lumen 114 is chosento make this reduction.

Alternatively or additionally, the thickness of ring 130, outer wall 102and/or inner wall 104 are chosen in order to reduce blood flow to aspecific level, regardless of the percentage change of flow reduction.

It should be appreciated that different features may be combined indifferent ways. In particular, not all the features shown above in aparticular embodiment are necessary in every similar exemplaryembodiment of the invention. Further, combinations of features fromdifferent embodiments into a single embodiment or a single feature arealso considered to be within the scope of some exemplary embodiments ofthe invention.

In addition, some of the features of the invention described herein maybe adapted for use with prior art devices, in accordance with otherexemplary embodiments of the invention. The particular geometric formsand measurements used to illustrate the invention should not beconsidered limiting the invention in its broadest aspect to only thoseforms. Although some limitations are described only as method orapparatus limitations, the scope of the invention also includesapparatus designed to carry out the methods and methods of using theapparatus.

Also within the scope of the invention are surgical kits, for example,kits that include sets of delivery systems and implants. Optionally,such kits also include instructions for use. Measurements are providedto serve only as exemplary measurements for particular cases, the exactmeasurements applied will vary depending on the application. When usedin the disclosure and/or claims, the terms “comprises”, “comprising”,“includes”, “including” or the like means “including but not limitedto”.

It will be appreciated by a person skilled in the art that the presentinvention is not limited by what has thus far been described. Rather,the scope of the present invention is limited only by the followingclaims.

1. A tubular implant for obstructing blood flow through a blood vessel,the implant comprising: an outer surface having a geometry of a tube, atleast a portion of which is adapted for contacting a blood vessel; andan inner surface defining a passage through which blood flows, whereinthe distance between the inner surface and the outer surface isnon-uniform along an axis of the tube.
 2. An implant according to claim1, wherein at least a portion of the inner and outer walls arecontinuous.
 3. An implant according to claim 1, wherein at least oneportion of the distance is hollow.
 4. An implant according to claim 3,wherein the at least one hollow portion is adapted to be inflated.
 5. Animplant according to claim 3, wherein at least one of the outer andinner surfaces is parallel to the longitudinal axis of the flow passage.6. An implant according to claim 3, wherein at least one of the outerand inner surfaces is non-parallel to the longitudinal axis of the flowpassage.
 7. An implant for obstructing blood flow in a blood vessel, theimplant comprising: a tubular wall defining a flow passage adapted forencircling a flow of blood through a vessel; and one or morepositionally adjustable flaps projecting from the wall into the bloodflow.
 8. An implant according to claim 7, wherein the one or more flapscomprise two or more flaps.
 9. An implant for obstructing blood flow ina blood vessel, the implant comprising: a tubular wall defining a flowpassage adapted for encircling a flow of blood through a vessel; two ormore positionally adjustable flaps each connected at one end to thetubular wall; and one or more guide elements connecting the two or moreflaps, operative to maintain the two or more flaps in a position inwhich they partially block the flow passage.
 10. The implant accordingto claim 9 wherein the one or more guide elements deform or break underpressure.
 11. The implant according to claim 9, wherein the one or moreguide elements comprise two or more guide elements.
 12. The implantaccording to claim 11 wherein the two or more guide elements havedifferent pressure thresholds at which they deform or break.
 13. Animplant for obstructing blood flow in a blood vessel, the implantcomprising: a tubular wall defining a flow passage adapted forencircling a flow of blood through a vessel; and at least onenon-overlapping flap projecting from the wall into the blood flow. 14.An implant according to claim 13, wherein the at least one flap issubstantially planar with a surface of the tubular wall.
 15. An implantaccording to claim 13, wherein the at least one flap is substantiallynon-planar with a surface of the tubular wall.
 16. An implant accordingto claim 13, wherein the at least one flap is positionally adjustable.17. An implant according to claim 13, wherein the at least one flapcomprises at least two non-overlapping flaps.
 18. An implant accordingto claim 13, comprising a kit that additionally includes a flap angleadjusting tool, the tool comprising a shaft having one or more wingprojections adapted to press against one or more flow obstructing flaps.19. The implant according to claim 18, wherein the one or more wings ofthe tool are activated in one or both of the following ways:mechanically; and inflatably.
 20. An implant for obstructing blood flowin a blood vessel, the implant comprising: a tubular wall defining aflow passage adapted for encircling a flow of blood through a vessel andleast one wire of varying effective width adapted to at least partiallyobstruct blood flow.
 21. An implant according to claim 20, wherein theat least one wire curves in a plane of the width of the wire.
 22. Animplant according to claim 20, wherein the at least one wire isconnected to an object.
 23. An implant according to claim 20, whereinthe at least one wire comprises at least two wires.
 24. An implantaccording to claim 23, wherein the at least two wires areinterconnected.
 25. An implant according to claim 24, wherein theinterconnection comprises at least one curved member.
 26. An implantaccording to claim 1, wherein at least a portion of the implant isadapted to change configuration upon absorption of fluid.
 27. An implantaccording to claim 1, wherein at least a portion of the implantcomprises resilient materials.
 28. An implant according to claim 1,wherein at least a portion of the implant comprises shape memorymaterials.
 29. An implant according to claim 1, wherein at least aportion of the implant is adapted to be inflated.
 30. A method ofmodifying an implant geometry, of a tubular implant with at least oneintra-luminal flap, comprising: contacting at least one intra-lumen flapof an implanted vascular implant with an effector element; and bendingsaid flap by applying force via said contact.
 31. A method according toclaim 30, wherein contacting comprises pulling said element towards saidflap.
 32. A method according to claim 30, wherein contacting comprisespushing said element towards said flap.
 33. A method according to claim32, wherein pushing comprises pushing with enough force to tear anelement restraining of said flap.
 34. A method according to claim 30,wherein said element comprises a mechanically expandable element.
 35. Amethod according to claim 30, wherein said element comprises amechanically expandable element.
 36. An implant comprising: a radiallyexpandable tubular sheath; and at least one flap welded to said sheathand configured to at least partially and rigidly obstruct a lumen ofsaid sheath.
 37. An implant according to claim 36, wherein said tubularsheath comprises a wire mesh sheath.
 38. An implant according to claim36, comprising at least two flaps and comprising at least onerestraining element interconnecting said flaps and limiting theirmovement relative to each other.
 39. An implant according to claim 38,wherein said restraining element is adapted to be torn by applying forceto one or more flaps, while implanted.